docs: def set_json_converters(encode, decode):
      """
      Modify the default JSON conversion functions. This affects all
      :class:`~couchbase.bucket.Bucket` instances.
  
      These functions will called instead of the default ones (``json.dumps``
      and ``json.loads``) to encode and decode JSON (when :const:`FMT_JSON` is
      used).
  
      :param callable encode: Callable to invoke when encoding an object to JSON.
          This should have the same prototype as ``json.dumps``, with the
          exception that it is only ever passed a single argument.
  
      :param callable decode: Callable to invoke when decoding an object to JSON.
          This should have the same prototype and behavior
          as ``json.loads`` with the exception that it is only ever
          passed a single argument.
  
      :return: A tuple of ``(old encoder, old decoder)``
  
      No exceptions are raised, and it is the responsibility of the caller to
      ensure that the provided functions operate correctly, otherwise exceptions
      may be thrown randomly when encoding and decoding values
      """
      ret = _LCB._modify_helpers(json_encode=encode, json_decode=decode)
      return (ret['json_encode'], ret['json_decode'])